PURPOSE: Tropomyosin receptor kinase (TRK) fusions are detected in less than 2% of central nervous system tumors. There are limited data on the clinical course of affected patients. EXPERIMENTAL DESIGN: We conducted an international retrospective cohort study of patients with TRK fusion-driven central nervous system tumors. RESULTS: A total of 119 patients were identified. The median age at the time of diagnosis was 4.5 years. The majority were reported to have a histology consistent with a diagnosis of high-grade glioma (HGG; 57.1%) followed by low-grade glioma (LGG; 27.7%). Pediatric patients had a better prognosis, with a median overall survival of 185.5 months compared with 24.8 months in adults (P < 0.0001). Patients with LGG also had a better outcome when compared with HGG (P = 0.0012). The objective response was 68.8% with larotrectinib compared with 38.1% for nontargeted treatment. CONCLUSIONS: Children with LGG had a favorable outcome compared with adult glioma and HGG. TRK inhibitors seem to improve tumor control.

• MeSH
• dítě MeSH
• dospělí MeSH
• fúze genů * MeSH
• fúzní onkogenní proteiny * genetika   MeSH
• gliom * genetika   farmakoterapie   patologie   mortalita   MeSH
• inhibitory proteinkinas terapeutické užití   MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nádory centrálního nervového systému * genetika   mortalita   patologie   farmakoterapie   diagnóza   MeSH
• předškolní dítě MeSH
• prognóza MeSH
• pyrazoly terapeutické užití   aplikace a dávkování   MeSH
• pyrimidiny terapeutické užití   aplikace a dávkování   MeSH
• receptor trkA * genetika   MeSH
• receptor trkB genetika   MeSH
• retrospektivní studie MeSH
• senioři MeSH
• výsledek terapie MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fúzní onkogenní proteiny * MeSH
• inhibitory proteinkinas MeSH
• larotrectinib MeSH Prohlížeč
• pyrazoly MeSH
• pyrimidiny MeSH
• receptor trkA * MeSH
• receptor trkB MeSH

Gliomas are the most common central nervous tumors in children and adolescents. However, spinal cord low-grade gliomas (sLGGs) are rare, with scarce information on tumor genomics and epigenomics. To define the molecular landscape of sLGGs, we integrated clinical data, histology, and multi-level genetic and epigenetic analyses on a consecutive cohort of 26 pediatric patients. Driver molecular alteration was found in 92% of patients (24/26). A novel variant of KIAA1549:BRAF fusion (ex10:ex9) was identified using RNA-seq in four cases. Importantly, only one-third of oncogenic drivers could be revealed using standard diagnostic methods, and two-thirds of pediatric patients with sLGGs required extensive molecular examination. The majority (23/24) of detected alterations were potentially druggable targets. Four patients in our cohort received targeted therapy with MEK or NTRK inhibitors. Three of those exhibited clinical improvement (two with trametinib, one with larotrectinib), and two patients achieved partial response. Methylation profiling was implemented to further refine the diagnosis and revealed intertumoral heterogeneity in sLGGs. Although 55% of tumors clustered with pilocytic astrocytoma, other rare entities were identified in this patient population. In particular, diffuse leptomeningeal glioneuronal tumors (n = 3) and high-grade astrocytoma with piloid features (n = 1) and pleomorphic xanthoastrocytoma (n = 1) were present. A proportion of tumors (14%) had no match with the current version of the classifier. Complex molecular genetic sLGGs characterization was invaluable to refine diagnosis, which has proven to be essential in such a rare tumor entity. Moreover, identifying a high proportion of drugable targets in sLGGs opened an opportunity for new treatment modalities.

• Klíčová slova
• KIAA1549:BRAF fusion, Low-grade glioma, Methylation profiling, NTRK fusion, Spinal cord,
• MeSH
• astrocytom * genetika   MeSH
• dítě MeSH
• genomika MeSH
• gliom * genetika   patologie   MeSH
• lidé MeSH
• mitogenem aktivované proteinkinasy kinas MeSH
• mladiství MeSH
• nádory míchy * genetika   MeSH
• nádory mozku * genetika   MeSH
• protoonkogenní proteiny B-Raf genetika   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• mitogenem aktivované proteinkinasy kinas MeSH
• protoonkogenní proteiny B-Raf MeSH

Pediatric low-grade gliomas (pLGG) are frequently driven by genetic alterations in the RAS-mitogen-activated protein kinase (RAS/MAPK) pathway yet show unexplained variability in their clinical outcome. To address this, we characterized a cohort of >1,000 clinically annotated pLGG. Eighty-four percent of cases harbored a driver alteration, while those without an identified alteration also often exhibited upregulation of the RAS/MAPK pathway. pLGG could be broadly classified based on their alteration type. Rearrangement-driven tumors were diagnosed at a younger age, enriched for WHO grade I histology, infrequently progressed, and rarely resulted in death as compared with SNV-driven tumors. Further sub-classification of clinical-molecular correlates stratified pLGG into risk categories. These data highlight the biological and clinical differences between pLGG subtypes and opens avenues for future treatment refinement.

• Klíčová slova
• RAS/MAPK pathway, brain tumor, low-grade glioma, molecular diagnostics, neurooncology, pediatric, risk stratification,
• MeSH
• dítě MeSH
• fúzní onkogenní proteiny genetika   MeSH
• genová přestavba * MeSH
• gliom klasifikace   genetika   patologie   MeSH
• kohortové studie MeSH
• kojenec MeSH
• lidé MeSH
• mitogenem aktivované proteinkinasy genetika   MeSH
• mladiství MeSH
• mutace * MeSH
• nádorové biomarkery genetika   MeSH
• nádory mozku klasifikace   genetika   patologie   MeSH
• neurofibromin 1 genetika   MeSH
• novorozenec MeSH
• předškolní dítě MeSH
• protoonkogenní proteiny B-Raf genetika   MeSH
• Ras proteiny genetika   MeSH
• regulace genové exprese u nádorů * MeSH
• stanovení celkové genové exprese MeSH
• variabilita počtu kopií segmentů DNA * MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• BRAF protein, human MeSH Prohlížeč
• BRAF-KIAA1549 fusion protein, human MeSH Prohlížeč
• fúzní onkogenní proteiny MeSH
• mitogenem aktivované proteinkinasy MeSH
• nádorové biomarkery MeSH
• neurofibromin 1 MeSH
• NF1 protein, human MeSH Prohlížeč
• protoonkogenní proteiny B-Raf MeSH
• Ras proteiny MeSH